The company now operates in 190 countries and 28,000 cities, and its founders expect the service to grow to 100 million annual bookings and revenue of $1 billion. (The site charges both host and guest service fees for each stay, based on a percentage of the total price.) Those numbers have been a wake-up call for the hospitality industry, and for the local regulators who are responsible for ensuring lodgings are licensed and taxed, and meet minimal standards for health, safety, and hygiene. Airbnb's hosts aren't subjected to any of these rules, the industry complains, and should be. Like other sharing economy innovators, Airbnb is now at the center of a legal maelstrom in cities around the world. In Airbnb's home town of San Francisco, tax collectors say hosts haven't paid any of an estimated $1.4 million in hotel taxes or registered as businesses. And New Orleans considers Airbnb listings in the French Quarter to violate laws against "rentals" of less than 60 days. Get the full story at Harvard Business Review and GigaOM